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- Creators: School of Life Sciences
- Member of: Theses and Dissertations
- Status: Published
Description
Human activities around the world are threatening scores of wildlife species, pushing them closer to extinction. In order to address what many conservationists view as a global biodiversity crisis, it is vital that more people are inspired to care about wild animals and motivated to act in ways that help protect them. The up-close experiences and personal connections that people form with wild animals in zoos accredited by the Association of Zoos and Aquariums (AZA) or the World Association of Zoos and Aquariums (WAZA) can help achieve this. However, it is not very well understood how different types of encounters within these zoos may inspire conservation mindedness and pro-environmental behaviors. During this thesis project, surveys were conducted at the AZA-accredited Arizona Center for Nature Conservation/Phoenix Zoo to understand how interactive, hands-on animal experiences within zoos differ from passively viewing zoo animals when it comes to inspiring people to care about conservation. The Phoenix Zoo is home to two different species of giraffes, and guests can view them from the front of the Savanna Exhibit. Guests can also participate in the Giraffe Encounter, which is a much more interactive, hands-on experience. After surveying guests at both locations, the results showed that fewer people at the Giraffe Encounter responded that they often engage in pro-environmental behaviors. This may indicate that the people who participated in the Giraffe Encounter came to the zoo more for recreation and entertainment than to learn about wildlife. Despite this, more people learned something new about nature or conservation at the Giraffe Encounter than they did at the Savanna Exhibit. On average, guests also felt that the Giraffe Encounter motivated them to learn more about how to help animals in the wild than the Savanna Exhibit did. Overall, there is a strong correlation between having an interactive, hands-on experience with a zoo animal and caring more about wildlife conservation. However, more research still needs to be done in order to conclusively provide evidence for causation.
ContributorsBurgess, Christa Noell (Author) / Schoon, Michael (Thesis director) / Minteer, Ben (Committee member) / Allard, Ruth (Committee member) / School of Life Sciences (Contributor) / School of Sustainability (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-12
Description
Cancer is a disease in which abnormal cells divide uncontrollably and destroy body tissue, and currently plagues today’s world. Carcinomas are cancers derived from epithelial cells and include breast and prostate cancer. Breast cancer is a type of carcinoma that forms in breast tissue cells. The tumor cells can be further categorized after testing the cells for the presence of certain molecules. Hormone receptor positive breast cancer includes the tumor cells with receptors that respond to the steroid hormones, estrogen and progesterone, or the peptide hormone, HER2. These forms of cancer respond well to chemotherapy and endocrine therapy. On the other hand, triple negative breast cancer (TNBC) is characterized by the lack of hormone receptor expression and tends to have a worse prognosis in women. Prostate cancer forms in the cells of the prostate gland and has been attributed to mutations in androgen receptor ligand specificity. In a subset of triple negative breast cancer, genetic expression profiling has found a luminal androgen receptor that is dependent on androgen signaling. TNBC has also been found to respond well to enzalutamide, a an androgen receptor inhibitor. As the gene of the androgen receptor, AR, is located on the X chromosome and expressed in a variety of tissues, the responsiveness of TNBC to androgen receptor inhibition could be due to the differential usage of isoforms - different gene mRNA transcripts that produce different proteins. Thus, this study analyzed differential gene expression and differential isoform usage between TNBC cancers – that do and do not express the androgen receptor – and prostate cancer in order to better understand the underlying mechanism behind the effectiveness of androgen receptor inhibition in TNBC. Through the analysis of differential gene expression between the TNBC AR+ and AR- conditions, it was found that seven genes are significantly differentially expressed between the two types of tissues. Genes of significance are AR and EN1, which was found to be a potential prognostic marker in a subtype of TNBC. While some genes are differentially expressed between the TNBC AR+ and AR- tissues, the differences in isoform expression between the two tissues do not reflect the difference in gene expression. We discovered 11 genes that exhibited significant isoform switching between AR+ and AR- TNBC and have been found to contribute to cancer characteristics. The genes CLIC1 and RGS5 have been found to help the rapid, uncontrolled growth of cancer cells. HSD11B2, IRAK1, and COL1Al have been found to contribute to general cancer characteristics and metastasis in breast cancer. PSMA7 has been found to play a role in androgen receptor activation. Finally, SIDT1 and GLYATL1 are both associated with breast and prostate cancers. Overall, through the analysis of differential isoform usage between AR+ and AR- samples, we uncovered differences that were not detected by a gene level differential expression analysis. Thus, future work will focus on analyzing differential gene and isoform expression across all types of breast cancer and prostate cancer to better understand the responsiveness of TNBC to androgen receptor inhibition.
ContributorsDeshpande, Anagha J (Author) / Wilson-Sayres, Melissa (Thesis director) / Buetow, Kenneth (Committee member) / Natri, Heini (Committee member) / School of Human Evolution & Social Change (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
In recent years, the Maine lobster industry, researchers, and policy makers have attempted to come together to set new regulations into place that will help slow the decline of right whale populations off the North Atlantic coast. Like many species, right whales were once abundant in the Atlantic before commercial whaling practices decimated populations to near extinction by the 1900’s (Fujiwara et al., 2001). Today’s populations total to approximately 450 individuals worldwide and continue to decline despite conservation efforts (Pace et al., 2017). Though commercial whaling no longer poses a threat to right whales, there are other factors that have proven to be detrimental to their survival. In particular, ship strikes and entanglement in fishing rope are the main causes for continued population decline (Knowlton et al., 2012).
One may ask, how is all of this connected specifically to the Maine lobster industry? It has been determined that approximately 80% of right whales currently have scars along their bodies as a result of being entangled in fishing rope. More specifically, the rope that right whales are becoming entangled in is the vertical line used by lobstermen that connects the lobster trap lying on the seafloor to a buoy at the surface. Not only can this entanglement lead to the drowning of individuals, but also a decreased birth rate among females due to stress should they successfully free themselves (Knowlton et al., 2012).
In an attempt to decrease entanglement rates and bring the decline in right whale populations to a halt, the state of Maine has been in the process of creating and implementing new policies, many of which will have an impact on the lobster industry. Regulations that have been considered include weakened vertical lines, modified gear marking, a change in rope color, reduction in traps, or even the introduction of new ropeless technology.
What perceptions do lobstermen in Maine have regarding the conservation of right whales and the possible regulations that could be put into place? To address this question, I posted a Google Forms survey link on a local Maine fishermen’s Facebook page in late December 2018 that remained open until the end of February 2019. The five-minute survey was to be completed on a voluntary basis to gather a convenient sample from the 15,000 members on the group page, of which not all were lobstermen. There was a total of 39 participants. The survey asked about opinions regarding a series of possible regulations that could possibly impact the lobster industry, should they be implemented. Additionally, the survey provided space for lobstermen to explain how past regulations had impacted them personally, as well as space for recommendations they thought would help conserve right whale populations while simultaneously creating little negative impact on the lobster industry.
One may ask, how is all of this connected specifically to the Maine lobster industry? It has been determined that approximately 80% of right whales currently have scars along their bodies as a result of being entangled in fishing rope. More specifically, the rope that right whales are becoming entangled in is the vertical line used by lobstermen that connects the lobster trap lying on the seafloor to a buoy at the surface. Not only can this entanglement lead to the drowning of individuals, but also a decreased birth rate among females due to stress should they successfully free themselves (Knowlton et al., 2012).
In an attempt to decrease entanglement rates and bring the decline in right whale populations to a halt, the state of Maine has been in the process of creating and implementing new policies, many of which will have an impact on the lobster industry. Regulations that have been considered include weakened vertical lines, modified gear marking, a change in rope color, reduction in traps, or even the introduction of new ropeless technology.
What perceptions do lobstermen in Maine have regarding the conservation of right whales and the possible regulations that could be put into place? To address this question, I posted a Google Forms survey link on a local Maine fishermen’s Facebook page in late December 2018 that remained open until the end of February 2019. The five-minute survey was to be completed on a voluntary basis to gather a convenient sample from the 15,000 members on the group page, of which not all were lobstermen. There was a total of 39 participants. The survey asked about opinions regarding a series of possible regulations that could possibly impact the lobster industry, should they be implemented. Additionally, the survey provided space for lobstermen to explain how past regulations had impacted them personally, as well as space for recommendations they thought would help conserve right whale populations while simultaneously creating little negative impact on the lobster industry.
ContributorsBolduc, Madison Creed (Author) / Gerber, Leah (Thesis director) / Jenkins, Lekelia (Committee member) / Bernard, Miranda (Committee member) / School of Life Sciences (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Lower termites are classified as termites that require a symbiotic relationship with their hindgut community of single-celled protozoa in order to gather nutrients to survive. The class Spirotrichonymphea is one of the six classes of protists that make up the Phylum Parabasalia. Within the class Spirotrichonymphea, there are 3 families and 11 genera. In this study, the Spirotrichonympha, Spironympha, and Microjoenia genera (family Spirotrichonymphidae), Holomastigotes genus (family Holomastigotidae), along with a new genus Brugerollea were targeted for molecular analysis. Protist cells were collected from Reticulitermes tibialis (Rhinotermitidae), Hodotermopsis sjostedti (Archotermopsidae), and Paraneotermes simplicornis (Kalotermidiae). Most molecular phylogenetic studies of termite-associated protists have used the 18S rRNA gene, however, there have been some ambiguities in the phylogeny of this gene. EF1-α, also known as EF1A, is a protein whose sequence can additionally be used to study the evolution of protists. EF1-α gene sequences were obtained from isolated protist cells by reverse transcription PCR (RT-PCR). Additionally, the 18S rRNA gene was amplified to confirm the isolated cells’ identity and compare the two phylogenetic methods, to see which would better resolve phylogenetic ambiguities. Sequences were compiled into an alignment for each target gene, and then a maximum likelihood tree was created for each using RAxML. Results from both trees supports the monophyly of Spirotrichonymphea and the polyphyly of genus Spirotrichonympha. However, neither gene fully resolves the phylogeny of Spirotrichonymphea.
ContributorsNguyen, Keana (Author) / Gile, Gillian (Thesis director) / De Martini, Francesca (Committee member) / Taerum, Stephen Joshua (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
In the study of the human brain’s ability to multitask, there are two perspectives: concurrent multitasking (performing multiple tasks simultaneously) and sequential multitasking (switching between tasks). The goal of this study is to investigate the human brain’s ability to “multitask” with multiple demanding stimuli of approximately equal concentration, from an electrophysiological perspective different than that of stimuli which don’t require full attention or exhibit impulsive multitasking responses. This study investigates the P3 component which has been experimentally proven to be associated with mental workload through information processing and cognitive function in visual and auditory tasks, where in the multitasking domain the greater attention elicited, the larger P3 waves are produced. This experiment compares the amplitude of the P3 component of individual stimulus presentation to that of multitasking trials, taking note of the brain workload. This study questions if the average wave amplitude in a multitasking ERP experiment will be the same as the grand average when performing the two tasks individually with respect to the P3 component. The hypothesis is that the P3 amplitude will be smaller in the multitasking trial than in the individual stimulus presentation, indicating that the brain is not actually concentrating on both tasks at once (sequential multitasking instead of concurrent) and that the brain is not focusing on each stimulus to the same degree when it was presented individually. Twenty undergraduate students at Barrett, the Honors College at Arizona State University (10 males and 10 females, with a mean age of 18.75 years, SD= 1.517) right handed, with normal or corrected visual acuity, English as first language, and no evidence of neurological compromise participated in the study. The experiment results revealed that one- hundred percent of participants undergo sequential multitasking in the presence of two demanding stimuli in the electrophysiological data, behavioral data, and subjective data. In this particular study, these findings indicate that the presence of additional demanding stimuli causes the workload of the brain to decrease as attention deviates in a bottleneck process to the multiple requisitions for focus, indicated by a reduced P3 voltage amplitude with the multitasking stimuli when compared to the independent. This study illustrates the feasible replication of P3 cognitive workload results for demanding stimuli, not only impulsive-response experiments, to suggest the brain’s tendency to undergo sequential multitasking when faced with multiple demanding stimuli. In brief, this study demonstrates that when higher cognitive processing is required to interpret and respond to the stimuli, the human brain results to sequential multitasking (task- switching, not concurrent multitasking) in the face of more challenging problems with each stimulus requiring a higher level of focus, workload, and attention.
ContributorsNeill, Ryan (Author) / Brewer, Gene (Thesis director) / Peter, Beate (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The oxygen sensitivity of hydrogenase is a large barrier in maximizing the efficiency of algal hydrogen production, despite recent efforts aimed at rewiring photosynthesis. This project focuses on the role of photosystem II (PSII) in extended hydrogen production by cells expressing the PSI-HydA1 chimera, with the goal of optimizing continuous production of photobiohydrogen in the green alga, Chlamydomonas reinhardtii. Experiments utilizing an artificial PSII electron
Therefore, it can be concluded that downstream processes are limiting the electron flow to the hydrogenase. It was also shown that the use of a PSII inhibitor, 3-(3,4-dichlorophenyl)-1,1- dimethylurea (DCMU), at sub-saturating concentrations under light exposure during growth temporarily improves the duration of the H2 evolution phase. The maximal hydrogen production rate was found to be approximately 32 nmol h-1 (µg Chl)-1. Although downregulation of PSII activity with DCMU improves the long-term hydrogen production, future experiments must be focused on improving oxygen tolerance of the hydrogenase as a means for higher hydrogen yields.
Therefore, it can be concluded that downstream processes are limiting the electron flow to the hydrogenase. It was also shown that the use of a PSII inhibitor, 3-(3,4-dichlorophenyl)-1,1- dimethylurea (DCMU), at sub-saturating concentrations under light exposure during growth temporarily improves the duration of the H2 evolution phase. The maximal hydrogen production rate was found to be approximately 32 nmol h-1 (µg Chl)-1. Although downregulation of PSII activity with DCMU improves the long-term hydrogen production, future experiments must be focused on improving oxygen tolerance of the hydrogenase as a means for higher hydrogen yields.
ContributorsO'Boyle, Taryn Reilly (Author) / Redding, Kevin (Thesis director) / Ghirlanda, Giovanna (Committee member) / Vermaas, Willem (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of Life Sciences (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
While some stress during pregnancy is normal, continuous stress during pregnancy could have negative lasting impacts on a child’s health. The type of stress that is harmful during pregnancy is “the kind that doesn’t let up” (Watson). This type of stress is chronic and is more intense than the normal stresses of everyday life. Researchers have shown that when fetuses are continuously exposed to such levels of stress, their bodies react in unhealthy ways. Given all the data showing that varying stressors experienced by pregnant women negatively affect their children’s postnatal health and development, it is important to identify the specific impacts of these stressors in order to understand how they affect the health of children.
By conducting a literature review, I have found a number of studies reporting links between a pregnant woman’s stress and the development of health issues in her child. For example, researchers of one study found that infants born to women who were depressed during pregnancy had early brain development issues and difficulty regulating emotions and stress (Hayes, et. al). In another study, researchers observed a positive association between maternal anxiety during pregnancy and asthma in offspring (Cookson, et. al). Such findings indicate the significance of the prenatal period in healthy child development. However, while we may suspect that there are some negative outcomes for children born to chronically stressed women, there was interestingly a lack of information in areas where we may expect to find effects on the child. This gap in the literature indicates that we do not fully understand the effects of stress during pregnancy, and it seems that we do not know what really seems important to know about mental health during pregnancy. Thus, the results reflect that the existing knowledge in this area is lacking, making it challenging for medical specialists to understand how they may best intervene in order to promote the healthiest pregnancies and children.
By conducting a literature review, I have found a number of studies reporting links between a pregnant woman’s stress and the development of health issues in her child. For example, researchers of one study found that infants born to women who were depressed during pregnancy had early brain development issues and difficulty regulating emotions and stress (Hayes, et. al). In another study, researchers observed a positive association between maternal anxiety during pregnancy and asthma in offspring (Cookson, et. al). Such findings indicate the significance of the prenatal period in healthy child development. However, while we may suspect that there are some negative outcomes for children born to chronically stressed women, there was interestingly a lack of information in areas where we may expect to find effects on the child. This gap in the literature indicates that we do not fully understand the effects of stress during pregnancy, and it seems that we do not know what really seems important to know about mental health during pregnancy. Thus, the results reflect that the existing knowledge in this area is lacking, making it challenging for medical specialists to understand how they may best intervene in order to promote the healthiest pregnancies and children.
ContributorsKeller, Carrie Angelique (Author) / Maienschein, Jane (Thesis director) / Abboud, Carolina (Committee member) / Historical, Philosophical & Religious Studies (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
When ants encounter liquid food, they have two options of transporting that food to their nests. The first is the social bucket method in which liquid is carried in the mandibles of the workers back to the nest. The second is trophallaxis in which liquid is imbibed and then transported inside the ant back to the nest. The liquid is then regurgitated to fellow nestmates. Ectatomma have been observed using the social bucket method of transport and were considered members of the Ponerine family. However, a new phylogeny created by Borowiec and Rabeling places Ectatomma near to Formecinae and Myrmicinae, both know for practicing trophallaxis. This seems to suggest either Ectatomma is able to utilize trophallaxis as well or that the evolutionary practice of trophallaxis is more plastic than previously believed. The ability of Ectatomma ruidum to utilize trophallaxis was examined in two experiments. The first experiment examined E. ruidum’s ability to practice worker to worker trophallaxis and the second examined E. ruidum’s ability to perform worker to larva trophallaxis. The results of both experiments indicated that E. ruidum cannot utilize trophallaxis but the larva of E. ruidum may be able to regurgitate to the workers. These results in turn seem to suggest that trophallaxis is a bit more plastic than originally thought.
ContributorsCunningham, Cassius Alexander (Author) / Pratt, Stephen (Thesis director) / Liebig, Juergen (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Prochlorococcus marinus (MED4), a genus of marine picocyanobacteria that proliferates in open oligotrophic ocean, is one of the most abundant photosynthetic microbes in the world, estimated to contribute up to 10% of the ocean’s primary production. The productivity of these microorganisms is controlled by macronutrient availability in the surface waters. The ratio of macronutrients in the ocean was defined, by Alfred Redfield, as an elemental ratio of 106C:16N:1P. However, the C:N:P ratio varies based on region, season, temperature and irradiance, as well as the composition of the primary producers. In oligotrophic gyres, these nutrient ratios are elevated from the Redfield stoichiometry, but whether this ratio exerts influence on the growth rate of the organism has not been investigated. Elemental stoichiometry of available nutrients can affect the aggregation of organic carbon and exportation of the particles to the ocean depths. The purpose of this study was to investigate the effects of nutrient limitation on aggregation and transparent exopolymeric particle (TEP) production which aids in aggregation. My findings suggested that nutrient limitation reduces TEP production and does not increase aggregate volume concentration. With continued warming, certain regions of the ocean will become more oligotrophic, which further decreases the nutrient supply available for Prochlorococcus. My research shows that this could lead to decreased exportation of organic carbon matter to the depths of the sea.
ContributorsRoy, Kevin Thomas (Author) / Neuer, Susanne (Thesis director) / Cadillo-Quiroz, Hinsby (Committee member) / Cruz, Bianca (Committee member) / Department of Psychology (Contributor) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
In the last 100 years, humans have grown increasingly dependent on synthetic plastic products. Companies have taken advantage of the low cost and convenience that plastics provide. However, the rise in plastic consumption has had unforeseen consequences. Due to plastic’s resistance to biodegradation the hazardous material has accumulated in the environment. While few plastics are recycled and placed in landfills, the majority of this waste will accumulate in the oceans where it threatens the health of marine wildlife. Ocean organisms often become entangled or consume plastic waste; in the majority of these cases death is inevitable. The consumption of plastics causes contamination throughout all marine trophic levels. Plastic toxins bio-accumulate in tissues. The toxins concentrate as they move up the trophic levels and harm life processes of marine organisms. A vital step in combating plastic pollution is educating the public. Children, in particular, need to understand the negative implications of plastic pollution because they will experience the consequences. The goal of this project is to spread awareness of plastic pollution to young children in an entertaining and emotional way. There are several approaches to publishing a successful children’s book; the story should be captivating, reliable, with a compelling story that the reader may relate too. For this project, three well-structured children’s books were examined for inspiration. A children’s book was then constructed to inform children of ocean plastic pollution.
ContributorsPluhar, Alexis Faye (Author) / Fette, Donald (Thesis director) / Foy, Joseph (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05